Indian students smear coloured powder during an event to celebrate the Hindu festival of Holi in Kolkata on February 26, 2018. Holi, the popular Hindu spring festival of colours is observed in India at the end of the winter season on the last full moon of the lunar month, and will be celebrated on March 1 this year. (Photo by Dibyangshu Sarkar/AFP Photo)

An aerial view shows a Russian Troika, a sledge drawn by three horses, competing on the ice-covered Yenisei River during the annual Ice Derby amateur horse race near the Siberian settlement of Novosyolovo, south of Krasnoyarsk, Russia March 17, 2018. (Photo by Ilya Naymushin/Reuters)

A photographer in Somerset, South West England captured the mating rituals of toads as several males attempt to mate with one female all at once. (Photo by John Waters/NPL)

A youth in costume hurries past a mural after dancing at the Sun Festival in Cotacachi, Ecuador, Sunday, June 24, 2018. Across the Andes, from the tip of Argentina as far north as Colombia, indigenous communities are gathering for the southern hemisphere's winter solstice to honor the ancient sun god. (Photo by Dolores Ochoa/AP Photo)

French President Emmanuel Macron performs at the Shrine Africa in Lagos on July 3, 2018. French President Emmanuel Macron has arrived in Abuja for a meeting with his Nigerian counterpart Muhammadu Buhari, in his latest attempt to forge closer ties with English- speaking Africa. (Photo by Ludovic Marin/AFP Photo)

Smoke rises from a replica of a T-Rex after it burst into flames at the Royal Gorge Dinosaur Experience in Canon City, Colorado, U.S. in this picture obtained from social media March 22, 2018. (Photo by Reuters/Royal Gorge Dinosaur Experience)

Beda Haemmerli drives his 1936 Ford Indy race car (front) through a steep turn during the Indianapolis in Oerlikon race demonstration at the Offene Rennbahn cycling track in Zurich's Oerlikon suburb, Switzerland July 24, 2018. (Photo by Arnd Wiegmann/Reuters)

In this photograph taken on April 28, 2018, Afghan children work at a coal yard on the outskirts of Jalalabad, Afghanistan. (Photo by Noorullah Shirzada/AFP Photo)